绿色矿冶

There is a small amount of cadmium in the materials in the lead smelting system, and most of the cadmium enters the soot after smelting in the smelting furnace, and the soot contains about 10%~20% cadmium. In this study, cadmium was leached by acid leaching, and the leach residue was returned to lead smelting system. Sponge cadmium was prepared by adding zinc powder to cadmium-rich solution, and zinc was recovered by electrodeposition system after replacement. The effects of sulfuric acid acidity, reaction temperature, reaction time, liquid-solid ratio and stirring speed on the leaching rate of cadmium and zinc were investigated. The results show that under the condition of sulfuric acid acidity of 50g/L, the liquid-solid ratio of 5∶1, the temperature of 50℃, reaction time of 2.0h, the stirring speed of 70r/min, the cadmium leaching rate of cadmium-containing soot is 95.24%, cadmium leaching effect is good. Using the above optimum test conditions, the production practice shows that the leaching rate of cadmium and zinc in cadmium ash are stable above 95%, and the purity of cadmium in sponge is above 95%.